He did not ever specify on or off chain or any specific restrictions in correlation to the use cases.
Then why he was against putting BitDNS on Bitcoin?
Piling every proof-of-work quorum system in the world into one dataset doesn't scale.
Bitcoin and BitDNS can be used separately. Users shouldn't have to download all of both to use one or the other. BitDNS users may not want to download everything the next several unrelated networks decide to pile in either.
The networks need to have separate fates. BitDNS users might be completely liberal about adding any large data features since relatively few domain registrars are needed, while Bitcoin users might get increasingly tyrannical about limiting the size of the chain so it's easy for lots of users and small devices.
See? If you want non-monetary use case, then use your own "dataset", to not disturb regular users, and take down their payments.